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geonames.usgs.gov/pls/gnispublic/f?p=gnispq:3:::NO::P3_FID:411646
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www.outfitters.com/illinois/hancock/laharpe.html (10 Aug 2010)
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www.outfitters.com/illinois/hancock/laharpe/lhgs/index.html (9 Aug 2010)
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en.wikipedia.org/wiki/La_Harpe,_Illinois (29 Jun 2010)
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geonames.usgs.gov/pls/gnispublic/f?p=gnispq:3:::NO::P3_FID:2395566